Your explanation makes sense, but the issue merits further analysis. The debt is, after all, a very high tax burden on public finances. I believe it is now the Canadian government's third largest spending item; we aren't talking about peanuts, here. We could certainly take a closer look at the merits of requiring the government to report to Parliament every year, as opposed to every three years.
You said all budgets reflected five-year forecasts. I have been in Parliament barely a year and a half, so this is only the second budget I have scrutinized. However, at another time, in another legislature, with the benefit of analysis, we realized that no five-year forecasts ever held true the following year. The next year's estimates were never in line with the forecasted figures.
Is that the case for the federal government as well? If so, what is the point of preparing five-year forecasts if they aren't valid the following year?